There is provided a main device of a cordless telephone system that performs communication with at least one additional device, each of which includes a search unit that intermittently searches for a radio wave generated from the main device, and a search stopping unit that stops execution of the search unit after a state in which the search unit does not receive a radio wave continues for a predetermined time. The main device includes a radio wave generating unit, an operation stopping unit that stops an operation of the radio wave generating unit, and a temporary returning unit that temporality recovers the operation of the radio wave generating unit and stops the operation of the radio wave generating unit after the additional device executes multiple searches by using the search unit after stopping the operation of the radio wave generating unit, but before the predetermined time elapses.